diff --git a/cc/builder.go b/cc/builder.go
index 7a3394a4d..8719d4f87 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -485,7 +485,7 @@ func transformSourceToObj(ctx ModuleContext, subdir string, srcFiles, noTidySrcs
 		coverageFiles = make(android.Paths, 0, len(srcFiles))
 	}
 	var kytheFiles android.Paths
-	if flags.emitXrefs {
+	if flags.emitXrefs && ctx.Module() == ctx.PrimaryModule() {
 		kytheFiles = make(android.Paths, 0, len(srcFiles))
 	}
 
@@ -664,7 +664,7 @@ func transformSourceToObj(ctx ModuleContext, subdir string, srcFiles, noTidySrcs
 		})
 
 		// Register post-process build statements (such as for tidy or kythe).
-		if emitXref {
+		if emitXref && ctx.Module() == ctx.PrimaryModule() {
 			kytheFile := android.ObjPathWithExt(ctx, subdir, srcFile, "kzip")
 			ctx.Build(pctx, android.BuildParams{
 				Rule:        kytheExtract,
diff --git a/java/base.go b/java/base.go
index b4f800bbd..1a6584bfb 100644
--- a/java/base.go
+++ b/java/base.go
@@ -1852,7 +1852,7 @@ func (j *Module) compileJavaClasses(ctx android.ModuleContext, jarName string, i
 	classes := android.PathForModuleOut(ctx, "javac", jarName).OutputPath
 	TransformJavaToClasses(ctx, classes, idx, srcFiles, srcJars, annoSrcJar, flags, extraJarDeps)
 
-	if ctx.Config().EmitXrefRules() {
+	if ctx.Config().EmitXrefRules() && ctx.Module() == ctx.PrimaryModule() {
 		extractionFile := android.PathForModuleOut(ctx, kzipName)
 		emitXrefRule(ctx, extractionFile, idx, srcFiles, srcJars, flags, extraJarDeps)
 		j.kytheFiles = append(j.kytheFiles, extractionFile)